S‑Scheme Heterojunctions\nbetween Nanoparticles\nof Cd<sub>0.8</sub>Mn<sub>0.2</sub>S and Cu<sub>2</sub>O for Photocatalytic\nHydrogen Evolution

Cd<sub>0.8</sub>Mn<sub>0.2</sub>S is a ternary particulate\nchemical\nsubstance that faces significant challenges with carrier recombination\nin the field of photocatalysis. To address this issue, we formed an\ninternal electric field and constructed S-scheme heterojunctions using\nCu<sub>2</sub>O and Cd<sub>0.8</sub>Mn<sub>0.2</sub>S nanoparticles,\nthereby reducing the recombination rate of photogenerated carriers.\nWe synthesized Cd<sub>0.8</sub>Mn<sub>0.2</sub>S using a hydrothermal\nmethod, followed by employing ultrasonic self-assembly to closely\ncouple Cd<sub>0.8</sub>Mn<sub>0.2</sub>S with Cu<sub>2</sub>O. In\nthis configuration, Cd<sub>0.8</sub>Mn<sub>0.2</sub>S acts as the\nelectron acceptor and Cu<sub>2</sub>O acts as the electron donor.\nThe Cd<sub>0.8</sub>Mn<sub>0.2</sub>S/Cu<sub>2</sub>O structure forms\na tight interface, providing the shortest transfer distance for electron\nmigration. The S-scheme heterojunction strategy effectively lowers\nthe chemical reaction barriers and facilitates vectorial separation\nof photogenerated carriers. Under 10 W white light illumination, the\nCd<sub>0.8</sub>Mn<sub>0.2</sub>S/Cu<sub>2</sub>O composite photocatalyst\ndemonstrates remarkable hydrogen evolution activity, achieving a hydrogen\nproduction rate of 40.06 mmol·g<sup>–1</sup>·h<sup>–1</sup>. This S-scheme interface strategy paves the way for\nthe structural design and large-scale application of highly active\nvisible light photocatalysts.